This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Approximately 2% of the U.S. population is chronically infected with hepatitis C virus (HCV). Chronic HCV infections result in significant liver disease, including cirrhosis and liver cancer in approximately 20% of infected individuals. The current therapy of interferon and ribavirin does not result in viral clearance in the majority of cases. The development of improved antiviral strategies to treat HCV chronic infection is essential for the control of this disease. This study evaluated a proprietary immunotherapeutic technology for the ability to stimulate the innate immune system and suppress hepatitis C virus (HCV) replication in HCV-infected chimpanzees. Two HCV chronically infected animals were chosen for this study. The study consisted of a one week pre-dose baseline period, three 21 day dosing periods with escalating doses of the immunotherapeutic administered by IV infusion, and a follow up bleed at 35 days after the last dosing period. Baseline, on study, and follow up bleeds and liver biopsies were obtained. The animals were monitored for safety profile by urinalysis, blood chemistries, CBC and coagulation profile. Liver biopsies were examined for viral RNA levels, changes in gene expression and changes in histopathology. HCV viral load was determined by TaqMan real time quantitative RT-PCR against sequences in the 5'NTR of HCV.